Test Pipe Fumes - Time for High Flow Cat!

[benk777]

I've been riding with a test pipe for the past month, and I think I've reached the point where I cannot stand the fumes anymore. I think it may be contributing to some very bad headaches lately as well. It's really bad when at a stop, but it's also there when driving as well, especially with the windows open. It seems like the only time it's not a problem is when the windows are up and the A/C is on. Anyone else feel the same?

So I'd like to resolve this by getting a high-flow cat, but only if that will get rid of the fumes and still give me performance at a similar level to the test pipe. I'm looking at a model that surpasport carries, a bolt on RT metallic substrate high-flow cat. Anyone have it? Has anyone made the same progression from test to high-flow cat? Any other high-flow cats that you would recommend?

I should have a test pipe for sale soon!

Thanks.

Ben

 

[JDMMA70]

I've been riding with a test pipe for the past month, and I think I've reached the point where I cannot stand the fumes anymore. I think it may be contributing to some very bad headaches lately as well. It's really bad when at a stop, but it's also there when driving as well, especially with the windows open. It seems like the only time it's not a problem is when the windows are up and the A/C is on. Anyone else feel the same?

So I'd like to resolve this by getting a high-flow cat, but only if that will get rid of the fumes and still give me performance at a similar level to the test pipe. I'm looking at a model that surpasport carries, a bolt on RT metallic substrate high-flow cat. Anyone have it? Has anyone made the same progression from test to high-flow cat? Any other high-flow cats that you would recommend?

I should have a test pipe for sale soon!

Thanks.

Ben

The only time i smell the fumes from my test pipe is when im stopped other times i dont and cant even tell its there.

 

[AGlobalThreat]

Even with a test pipe you shouldn't be able to smell your exhaust from the interior (Unless you're stopped and wind is blowing the exhaust to the front of the car). If your exhaust extends all the way to the back of the car I'd check for exhaust leaks first.

 

[mkIIIman089]

I can't smell a thing except for a brief couple seconds with the windows down after coming to a stop, while the air overtakes the now stopped car.

 

[JDMMA70]

I can't smell a thing except for a brief couple seconds with the windows down after coming to a stop, while the air overtakes the now stopped car.

Same here,

When i had an exhaust leak where my downpipe and elbow connect i could smell the fumes coming through the A/C Vents, fixed that the next day. Just a thought if your problem sounded like mine did

 

[adampecush]

As others have mentioned, it sounds like you've got a leak, and probably in the engine bay. Rule out the manifold, turbo-manifold, and turbo-dp gaskets before changing anything major. putting a cat on with a leak won't change what you are smelling as it is likely escaping before the test pipe.

Also, if you don't end up having any leaks, make sure all body seals at the rear of the car are still ok (hatch, tail lights, etc).

 

[benk777]

I haven't noticed any audible exhaust leaks. And this all started after installing the test pipe.

Ben

 

[benk777]

As others have mentioned, it sounds like you've got a leak, and probably in the engine bay. Rule out the manifold, turbo-manifold, and turbo-dp gaskets before changing anything major. putting a cat on with a leak won't change what you are smelling as it is likely escaping before the test pipe.

Also, if you don't end up having any leaks, make sure all body seals at the rear of the car are still ok (hatch, tail lights, etc).

The rear could be suspect, as I do get water back there. But again, wasn't a problem before the test pipe.

Ben

 

[adampecush]

i didn't hear any exhaust leaks either, but when I ripped the DP off, a good portion of the gasket was burned away. I can pretty much guarantee you you'll find the same thing.

 

[benk777]

i didn't hear any exhaust leaks either, but when I ripped the DP off, a good portion of the gasket was burned away. I can pretty much guarantee you you'll find the same thing.

Well, I'm running the ebay recirc ddp that I purchased from 935. And I just used the gaskets that came with it, but I'm not sure what other gaskets I could use. Those were specifically made for this application, I think. Any advice?

Ben

 

[adampecush]

The stock toyota gasket is usually whats best, as it is a multi-layer steel gasket instead of the impregnated composite gaskets that come with those kits. Make sure you've torqued all bolts to spec as well. As a last resort, you could get away with applying a thin layer of exhaust cement to each side of the gasket to help with sealing.

 

[AGlobalThreat]

this all started after installing the test pipe.

Ben

Then you know where your problem is..

Check the gaskets for the test pipe and make sure its sealed tight.

 

[tekdeus]

YES, I installed a Magnaflow 3" hi-flow cat because I was tired of the smell also. It made a huge improvement, my exhaust doesn't stink anymore. But yes, I think you'll probably have a couple of spots in the hatch where exhaust is rising up and creeping into the interior, through either hidden rust holes or missing body plugs, which is why it stinks so much with a test pipe. This was the case with my car, no exhaust leaks.

As for power, my car still pulls very hard. I doubt I lost more than 6hp.

 

[tbcmorris]

It does sound like you have a leak....check that first. Exhaust exsiits the rear so if you don't have leak you shouldn't smell anything.

 

[pnutcar]

I had no fumes w/ my hi flo cat, my test pipe, or open dp. :dunno: None w/ my open wastegate dump either.

 

[GotBoost?]

What is your gas mileage? Do you have an aftermarket bov that's venting to the atmosphere? Have you checked the intercooler piping to rule out a boost leak? A boost leak would make you run rich. Maybe you're running way rich, and that you're smelling unburnt gas. My $0.02

 

[mkiii222]

What is your gas mileage? Do you have an aftermarket bov that's venting to the atmosphere? Have you checked the intercooler piping to rule out a boost leak? A boost leak would make you run rich. Maybe you're running way rich, and that you're smelling unburnt gas. My $0.02

+1

I've been running a test pipe for a while and don't smell a thing other than a small amount of burnt oil here and there (valve stems). Even standing behind the car with it running.

 

[JDMMA70]

What is your gas mileage? Do you have an aftermarket bov that's venting to the atmosphere? Have you checked the intercooler piping to rule out a boost leak? A boost leak would make you run rich. Maybe you're running way rich, and that you're smelling unburnt gas. My $0.02

Thats a good point, the OP should check out, im running a GReddy Type S that is vented, but the valve isnt open at idle only after i boost, took a while playing with the spring setting. When im at stop lights ill get a whif every now and then.

 

[benk777]

Good thought! I do have an hks bov that is vented to the atmosphere. When I get my cooleeze pipes this week I'll run it rerouted to see if that helps. I'll update after.

Ben

 

[benk777]

Another possibility is that I removed the drain piece from the spare tire well. Maybe when the windows are open it's causing air to be sucked in there from below the car. Seems unlikely however and doesn't explain the stoplight situations.

Ben